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authorMark Dickinson <dickinsm@gmail.com>2009-04-07 11:53:52 +0000
committerMark Dickinson <dickinsm@gmail.com>2009-04-07 11:53:52 +0000
commit638805f8603f6ac8fb5cef6fcc2017fa41925416 (patch)
treed3ed092cedbba4999d1b38ffe78d9b5069758253 /Python/atof.c
parent79d0b0e0ad577b2cca14d27d501beab04a57470c (diff)
downloadcpython-git-638805f8603f6ac8fb5cef6fcc2017fa41925416.tar.gz
Revert removal of atof.c and strtod.c in r71341. We're not quite
ready for this yet---this removal should happen as part of the py3k-short-float-repr merge.
Diffstat (limited to 'Python/atof.c')
-rw-r--r--Python/atof.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/Python/atof.c b/Python/atof.c
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index 0000000000..8fbde38472
--- /dev/null
+++ b/Python/atof.c
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+
+/* Just in case you haven't got an atof() around...
+ This one doesn't check for bad syntax or overflow,
+ and is slow and inaccurate.
+ But it's good enough for the occasional string literal... */
+
+#include "pyconfig.h"
+
+#include <ctype.h>
+
+double atof(char *s)
+{
+ double a = 0.0;
+ int e = 0;
+ int c;
+ while ((c = *s++) != '\0' && isdigit(c)) {
+ a = a*10.0 + (c - '0');
+ }
+ if (c == '.') {
+ while ((c = *s++) != '\0' && isdigit(c)) {
+ a = a*10.0 + (c - '0');
+ e = e-1;
+ }
+ }
+ if (c == 'e' || c == 'E') {
+ int sign = 1;
+ int i = 0;
+ c = *s++;
+ if (c == '+')
+ c = *s++;
+ else if (c == '-') {
+ c = *s++;
+ sign = -1;
+ }
+ while (isdigit(c)) {
+ i = i*10 + (c - '0');
+ c = *s++;
+ }
+ e += i*sign;
+ }
+ while (e > 0) {
+ a *= 10.0;
+ e--;
+ }
+ while (e < 0) {
+ a *= 0.1;
+ e++;
+ }
+ return a;
+}